文件位置：Location: ./application/config/constants.php
配置系统常量
1、当文件系统工作的时候检查并配置这些首选项
文件系统运行的时候这些默认的值会适当的增加系统的安全性，但是在php或apache的底层单独的为每各用户开一个进程的时候，使用八进制的值永远是正确的
FILE_READ_MODE 读取文件的模式
FILE_WRITE_MODE 写入文件的模式
DIR_READ_MODE 读取目录的模式
DIR_WRITE_MODE写入目录的模式
2、文件流模式
当我们使用fopen()/popen()的时候需要这些模式
define("FOPEN_READ","rb");
define("FOPEN_READ_WRITE","r+b");
define("FOPEN_WRITE_CREATE_DESTRUCTIVE","wb");
define("FOPEN_READ_WRITE_CREATE_DESTRUCTIVE","w+b");
define("FOPEN_WRITE_CREATE","ab");
define("FOPEN_READ_WRITE_CREATE","a+b");
define("FOPEN_WRITE_CREATE_STRICT","xb");
define("FOPEN_READ_WRITE_CREATE_STRICT","x+b");
文件源码：
<?php if ( ! defined("BASEPATH")) exit("No direct script access allowed");
/*
|--------------------------------------------------------------------------
| File and Directory Modes
|--------------------------------------------------------------------------
|
| These prefs 控制台、首选项 are used when checking and setting modes when working
| with the file system. The defaults are fine 罚款 on servers with proper
| security, but you may wish (or even need) to change the values in
| certain environments (Apache running a separate process for each
| user, PHP under CGI with Apache suEXEC, etc.). Octal values should
| always be used to set the mode correctly.
|
*/
define("FILE_READ_MODE", 0644);
define("FILE_WRITE_MODE", 0666);
define("DIR_READ_MODE", 0755);
define("DIR_WRITE_MODE", 0777);
/*
|--------------------------------------------------------------------------
| File Stream Modes 文件流模式
|--------------------------------------------------------------------------
|
| These modes are used when working with fopen()/popen()
|
*/
define("FOPEN_READ", "rb");
define("FOPEN_READ_WRITE", "r+b");
define("FOPEN_WRITE_CREATE_DESTRUCTIVE", "wb"); // truncates existing file data, use with care
define("FOPEN_READ_WRITE_CREATE_DESTRUCTIVE", "w+b"); // truncates existing file data, use with care
define("FOPEN_WRITE_CREATE", "ab");
define("FOPEN_READ_WRITE_CREATE", "a+b");
define("FOPEN_WRITE_CREATE_STRICT", "xb");
define("FOPEN_READ_WRITE_CREATE_STRICT", "x+b");
/* End of file constants.php */
/* Location: ./application/config/constants.php */